The twenty names are convincingly chosen, among them Ptolemy, Perdiccas, Eumenes the royal secretary, Philip the royal doctor, Philip the Greek engineer, Nearchus the admiral and Peucestas the persophile. All twenty men are known independently to have had reason to be at Babylon and most of them may have been at Medius's dinner. Fourteen of them, moreover, are said to have had the strongest possible reason for attending. That night, there was a devious plot to poison the king. They knew about it and they approved.

The plot itself is said to have been planned in Europe months before, where it centred on Antipatcr's family. As the pamphlet points out, motives for Antipater are not hard to imagine: the endless abuse of the reigning queen Olympias, the slow but menacing approach of Craterus and the veterans, the orders for his summons to Asia, the execution of old friends like Parmenion or relations like Alexander the Lyncestian, all these grievances might have urged him to self-defence. Two of his sons were already at Babylon and he had recently sent Cassander, the third and most forceful, to join them. He was equipped, said the pamphlet, with a small iron casket of poison, encased in the hoof of a mule, the only material which was strong enough to contain it. Many later believed that this poison was ice-cold water from the deadly river Styx, which flowed through the mountains of Arcadia before going down to the Underworld; but Arcadia was far from Antipater, and the modem Mavroneri falls, site of the ancient Styx, belie the ancients' belief in the power of its hellish water.

Cassander's arrival at Babylon in the last months of Alexander's life is a historical fact: it is true, too, that seven years later, he would show himself to be an implacable opponent of the king's memory and even murder Olympias, while gossip maintained that he could not look on Alexander's statue without feeling faint and uneasy. Once there, the pamphlet continued, he was to hand the poison to his brother Iollas and make ready his escape, as Iollas was butler to the king and could mix the poison into the royal wine without being noticed: all he needed was the occasion, none more convenient than Medius's banquet, as Medius, said the pamphlet, was in love with him. If the party was in honour of Heracles's death, there would be no risk of a change in Alexander's drinking habits. 'A cup of Heracles' was traditionally circulated and Alexander, rival and descendant of Heracles, was sure to be the first to drink from it. The poison's entry seemed assured.

The pamphlet mentions more accomplices than Medius and the butler. Of the twenty guests, only six are said to have been innocent: Ptolemy, Perdiccas, Eumenes and three others. The remaining fourteen, Nearchus and Philip the doctor included, were to keep up a suitable conversation while their Alexander drank doctored wine. They had all sworn oaths of secrecy and they hoped to profit personally from a change of king.

On the night of the banquet, said the pamphlet, all went as planned. Alexander drank from his cup and 'all of a sudden, he shouted with pain as if struck through the liver with an arrow'. After a few minutes, he could bear it no longer. He told the guests to continue drinking and he left for his bedroom, a doomed man. Amid all tins sensational detail only one fact is certain: those who had been present at the banquet did not wish their names to be published. They may have been guilty; they may only have feared the inevitable slander. The sequel alone can help to decide.

If Alexander had indeed been poisoned, the dose must have been enough to kill him beyond any doubt. There was no point in giving him half or doubtful measures, and even without cyanide the ancient world had enough herbal knowledge to produce an infallible poison. Strychnine, for instance, had long been extracted from nux vomica, known to Aristotle's school, and it would certainly have killed a young Macedonian. But its effects are more or less instantaneous, and here the timing of Alexander's death becomes important; fortunately, its published date is the one well-attested fact in the whole affair. From a contemporary Babylonian calendar, Alexander is known to have died on 10 June, whereas Medius's banquet, according to its only precise date, took place on 29 May; the king, therefore, had been reported ill for more than ten days, and whatever killed him, it cannot have been strychnine or any other instant poison. There are other possibilities, more remote, and there are confusions in ancient medicine which may be relevant, but in the absence of a ready poison, the alternative document deserves to be considered. It is nothing less than Alexander's Royal Diaries.

Round these Diaries, believed in antiquity to have been published by Eumenes the royal secretary and a certain Diodotus, there hangs an air of insoluble mystery. Quite suddenly, in the last days of the reign, the Diaries are quoted by later secondary sources for a day-by-day account of Alexander's business; to the frustration of historians, for whom only three long quotations now survive, they show him hunting birds and foxes, banqueting or playing dice, and all these activities seem to concentrate on his final month in Babylon. So, perhaps, did the whole work, but those who could read it in its entirety had noted how it kept referring to the king's recurrent drinking parties, even to his all-day sleeping in order to recover from a nocturnal debauch. This frankness is very remarkable. Alexander's drinking habits rapidly became a delicate subject, partly because of gossip, partly because the murderer of Cleitus had not always embraced sobriety: twenty-five years or so later, Aristobulus would plead, against the facts, that 'Alexander only sat long over his wine for the sake of conversation', like a portly country gentleman. And yet here, allegedly, was Eumenes the former secretary publishing a detailed diary of the king's continual carousing; our three brief extracts describe five debauches in the last month, each of which took thirty-six hours to sleep off before Alexander could begin to hunt, drink and dice again. The purpose of this strange publication can only be deduced from its contents.

These contents are insistent to the point of tedium. The month of the king's death began, it said, with a string of drinking-parties, one with Eumenes, another with Perdiccas, another at the 'house of Bagoas', not the eunuch but the former Vizier, whose country seat near Babylon was famous for rare date-palms and agreed to be royal property. It was eight years since Alexander had bestowed it on Parmenion as a reward. On each occasion Alexander spent the whole of the next day asleep, recovering his strength. On 29 May, after this series of nightly debauches, Alexander dined very late with his friends, drank still later with Medius, left the room unharmed, bathed, slept and returned the following day to 'drink once more far into the night'. This time, he left for the bath, ate a little but fell asleep in the bathroom, 'because he was already beginning to feel feverish'. Medius's party, so far from proving fatal, was followed by a repeat on the very next day and only then did Alexander sicken, not after a cup of poison, but after a bath, a sleep and a fever.

It is very hard not to sense a deliberate bias in the tone of such a Diary. Alexander, it seems to stress, did nothing unusual by drinking hard at Medius's banquet, for he had been drinking hard throughout the preceding month. Moreover, drink did not kill him, but an incidental sickness. The accounts of the following days are equally silent about poison. The next day, Alexander was carried out on a stretcher to sacrifice to his usual gods, Ammon no doubt among them, and he then lay in his bedroom instructing his officers in detail about the expedition to Arabia which he still intended to begin in four days' time. He was later carried by boat to the park on the far side of the Euphrates, probably the summer palace of Nebuchadnezzar in the cooler and northerly city-quarter; there, he continued to sacrifice, bath, talk to the officers and play dice with Medius, though his fever lasted all night. But the next day he took a marked mm for the worse and could not even manage to sacrifice. A move to the 'palace near the swimming-pool' did not improve him, though for the next two days, the Diaries still insist that he continued to instruct the officers about the voyage. At last, even the officers were ordered to wait outside in the courtyard and on 7 June a very sick king indeed was moved back by boat to the main palace where his fever had first broken out. When his officers came to see him he could no longer speak; on 8 and 9 June it was the same, and on the evening of the 9th, there occurred the only incident on which the Diaries and the pamphlet agreed: the common troopers rioted.